Calpha
Calpha is a giant planet made largely of water. It orbits a binary star consisting of two Sun-size yellow stars. Because of its plentiful light and plentiful water and a small moon's worth of dissolved nutrients, Calpha is just about the easiest planet in the galaxy for life and boasts a biodiversity to rival Tolb. Malacutia is a notable moon of Calpha, and Arnost shares Calpha's stars. The name of Calpha is thought to be based on its original name Alpha, part of a Greek-letter naming convention used during the Ancient Space Age. Geology Calpha's inner core is composed mostly of molten nickel, surrounded by a thick layer of molten rock and iron, and an outer core of solid rock. This outer core is sponge-like in shape, full of caves and tunnels. The core is about 15,000 km in radius and includes some peculiar currents in which an unidentified form of matter is highly concentrated. These currents somehow produce a strong anti-gravity field that is felt throughout much of Calpha's mass, and prevents the astronomical pressures that would otherwise result from so much water. In fact, Calpha's highest water pressures are about halfway between the core and surface, and are only double those found on Earth. The bulk of Calpha's volume is liquid water, with a total planetary radius of about 40,000 km. On the surface, giant floating coral masses serve as islands, the largest are about the size of North America. Only the smallest of Calpha's coral islands feel any bobbing effect from waves. Islands do change in altitude significantly due to tides, but since the swells of water push the atmosphere up, too, nobody can really tell unless they're doing astronomy. Calpha has two polar ice caps which fluctuate in size depending on the temperature of surrounding currents. Sometimes an island drifts into the polar regions, and while this is disastrous for life on the island, it just merges into the glaciers and eventually makes its way out, usually centuries later. Ecosystem Surface Water Plants Being an ocean planet, the vast majority of Calpha's plant biomass is phytoplankton, serving as the basis for the aquatic food web. There are also larger floating kelp beds that serve as a food source and shelter for larger creatures, similar to an upside-down forest. Animals Calpha is home to an uncountable variety in every niche of the aquatic ecosystem. The most famous of these is the Calpha Sea Monster, which is itself a generalized name for several intelligent species with legendary qualities like nearly impenetrable skin and highly potent venom. Relatives of the Calpha Sea Monster are the Dragonfish, powerful swimmers mostly used as beasts of burden and able to shoot oil-covered pellets of pure sodium that explode violently after a certain distance. Other species observed in the upper expanses of Calpha's seas include an aquatic type of Xillo Beast, usually accompanied by swarms of Platypus Bats, relatives of bats that have thicker wings for swimming, a duckbill, and venomous spines. Platypus Bats mostly eat fish, but occasionally climb on land to forage for berries. There is also the Lightning Eel, an electric eel in its own right, but more notable as the fastest long-distance swimmer known to science, with a small population having been trained by native societies as messengers between islands. The shallow waters near islands are home to a similar diversity of life. One brown arachnid is intelligent enough to only prey upon skin parasites of larger creatures who will protect it. The Phobocoluberus (Terror Snake) is a thick-bodied, 6-meter snake whose venom causes intense paranoia and hallucinations, usually leading to death by heart attack within minutes. The Calphian kraken, known locally as the Krakaken, is a squid-like creature reaching over 20 meters in length, with eight tentacles around its mouth and three larger arms at the base of its head, and external shell armor covering much of its lower body. While Calpha boasts a surprisingly high amount of nutrients in the water, they are nowhere near evenly mixed, leaving vast areas of open ocean virtually devoid of the ingredients for life. Thus, creatures must be either migratory or have some innovative way of generating their own food and energy. One particularly large type of whale, dubbed the Great Dag-Gadol Fish, has the unique adaptation that its mouth, lungs, and stomach have all fused into a gigantic inner cavity that is filled with air and is home to its own small ecosystem that cycles oxygen and nutrients, including trees, fungi, and some small insects. The whale's true mouth is at the back of this cavity, reaching forward occasionally to eat some of the plant life there; this whale lives near the bottom of the sunlit zone, and its translucent top allows its inner plants to photosynthesize. It has two layers of lips that are tightly sealed to keep the air inside from escaping, but will serve as a sort of airlock to ingest falling food debris from the ocean outside to replenish nutrients on the inside. In this way some living individuals have been swallowed and survived for years, living off the plants in the cavity before escaping in perfect health. Another unclassifiable creature breeds near islands, but upon reaching adult size swims out into the open ocean, thousands of miles from any predator, and uses a not-yet-understood mechanism to filter deuterium (a relatively rare hydrogen isotope) from the seawater and fuel a small fusion reaction in its gut, thus providing all the energy it needs. Deeper in the seas live the Giant Sea Slug, a blind, particularly stupid, whale-sized worm with a powerful jaw and sharp teeth that will gnaw at anything whatsoever that falls from the surface. Civilization The Green Calphians are a green-skinned, humanoid, aquatic people with gills, webbed hands and feet, large eyes, and short tails. They live in sprawling, free-floating cities that lie just beneath the surface, and have developed rather robust aquatic technology, including weapons, communications, and vehicles. While they have the technical capabilities of some spacefaring civilizations, Green Calphians have little that even flies in the air, since there is so much more room beneath the surface and because they breathe water, which is a lot heavier to take with you into space. They are also responsible for domesticating and breeding a number of species, including a crustacean called Chayrs, which are for all purposes living and walking chairs and are great for leisurely transport. The second most populous civilization on Calpha is the Jellymen, a race of essentially intelligent jellyfish who coil their tentacles into functional bodies. They have rudimentary eyes, but well-developed brains, muscles, multicolored bioluminescence, and electric communication that is detectable to some fish (like sharks and their Green Calphian neighbors) but appears to humans as telepathy. Since most of their bodies are simply coils of tentacles, they can rearrange themselves for any purpose, and will often take a humanoid shape when dealing with Green Calphians and off-planet visitors. Jellymen live well below the surface, only occasionally venturing to Green Calphian cities to trade, mostly to get technology in exchange for valuable leftovers from their meals such as tusks and hides. They live in pods of hundreds to thousands, with a flexible social structure in which a small team does all the hunting, which they find quite fun. Islands Islands on Calpha are composed of vast colonies of coral that produce buoyant, rocky residue. The living colony is on the underwater side of the island, so as it grows deeper, the island floats higher, and natural erosion returns highest material to the sea. The ecosystems on the surfaces of these islands are for the most part similar to those of other rocky environments, including grasses, trees, and the rest. Animals Animal life varies from island to island, often even more so than between continents on smaller planets, because islands on Calpha are typically very far apart. One island's primary herbivores are large, guinea-pig-like rodents, who are preyed upon by Raprotines, a reptile with dinosaur-like biology and a wolf-like body structure. The largest islands are home to the planet's largest land animal, the Tyrannosaurus Imperator, with females reaching 40 m in length. Another dinosaur native to Calpha is the human-height Saevoraptor, intelligent enough to learn basic interactions with linguistic species, but will apply all their intelligence to hunting. Other islands boast Arc Stalkers, horse-sized felines who generate a large electric charge to stun their pray when pouncing. These are preyed upon by the Wolf Snake, a 3-meter variety of pit viper that hunts in packs and has long, metal horns on its nose that connect to a metal stripe that reaches to its mid belly, thus safely diverting Arc Stalker charges away from internal organs. Another notable hunter is the saber-toothed giant rat, famous for hunting Peripat Fish, which are a diverse group of air-breathing fish who walk around on two muscular legs and exhibit social behavior roughly analogous to flocks of birds. Then there is the Pond Monitor, a 10-meter monitor lizard with chameleon-like camouflage that is a pond-dwelling ambush predator. Other ambush predators include the Hydra, a gigantic two-headed serpent that prefers caves and rocky coastlines, the Dragon Tortoise, a 1.5 m tall ambush predator with very strong, serrated jaws, and crocodilians of normal to giant proportions. Pyrosaurus, originally thought to be a fire-breathing theropod, is actually a wingless dragon with bright blue skin and glowing orange eyes that can project a 15-meter stream of flame from its specially-shaped mouth for up to 20 seconds at a time; like all native Calphian dragons, they mate for life and will protect their offspring with their lives. Other dragons on Calpha include Wyvern dragons and semi-aquatic Plesioth dragons. Civilization There are cities on most of the larger islands, just like on any rocky planet, with the notable difference that there is no mining or drilling industry, since the islands are made of fairly uniform coral rock in its various forms. Most cities have developed recently as colonies from other planets. However, some islands are protected as the home of the White Calphians, a civilization of sand-colored lobster-like people with an upright head that stands roughly a meter from the ground. The White Calphians enjoy architecture for its own sake and have created intricate cities that house a rather simple society. They are also quite territorial, doing trade with Green Calphians and offworlders only off of their shores and never on land, and caring little for the goings-on of other islands or sea life on their planet. Core Many strange creatures and glowing bacteria live in the tunnels and caves of the outer core. All over the core, geothermal vents spew superheated and mineral-rich water, fueling ecosystems much like on Earth, except vastly larger and more diverse. A particularly prevalent species is the Fry Worm, an extremely heat-tolerant, scavenging omnivore which is technically a snake with a very small mouth. These are preyed upon by Thunder Rays, who hunt using electric shock and can reach wingspans of up to 15 meters; they are territorial, warning intruders with thunderclaps created by arcing electricity between their curled fins. The electric shocks that these rays produce is so powerful that a great amount of money has gone into attempts (so far unsuccessful) to transport them off-planet for military use. Also living near geothermal vents are small, intelligent, transparent tick-like creatures that live in large communities, even cities made from minerals harvested from the vents.